We present photometric and spectroscopic observations of the
gamma-ray burst GRB 021211 obtained during the late stages of its
afterglow. The light curve shows a rebrightening occurring ~25 days after the GRB. The analysis of a VLT spectrum obtained during
the bump (27 days after the GRB) reveals a suggestive resemblance with
the spectrum of the prototypical type-Ic SN 1994I, obtained ~10 days past maximum light. Particularly we have measured a strong,
broad absorption feature at 3770 Å, which we have identified with Ca II blueshifted by ~ km s-1, thus indicating that a
supernova (SN) component is indeed powering the “bump” in the afterglow
decay. Assuming SN 1994I as a template, the spectroscopic and
photometric data together indicate that the SN and GRB explosions were
at most separated by a few days. Our results suggest that GRBs might be
associated also to standard type-Ic supernovae.

Key words: gamma rays: bursts / supernovae

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Based on observations made with ESO telescopes under programmes
70.D-0412 and 270.D-5022.

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